[GIS] Changing Layer Definitions / Refresh Not Behaving in ArcGIS API for JavaScript

arcgis-javascript-api

In ArcGIS Javascript API 3.3, I have an ArcGISDynamicMapService layer in my application that points to a fairly simple (6 layers) map service. In the application, there is a GUI/widget that allows the user to pick various options – which then dynamically changes the layer's layerDefinitions property to re-render the layer based on their selection.

After I define and set the layerDefinitions of the layer, I call the layer.refresh method to re-render the layer. However, the re-rendered layer is always wrong – either the wrong layers are rendered, or wrong features are rendered, and there doesn't appear to be any pattern in these errors that I can determine. However, once the map is panned or zoomed, the re-rendered layer is drawn exactly as expected. Below is the relevant javascript code. The "format" function is a .NET-like string formatting function I've added to the script.

var layerDefinitions = [];
layerDefinitions[1] = "TransmitterId IN ({0})".format(visibleTransmitterIds.join(","));
layerDefinitions[2] = "TransmitterId IN ({0})".format(visibleTransmitterIds.join(","));
analysisResultLyr.setLayerDefinitions(layerDefinitions);
analysisResultLyr.refresh();

Using various http sniffing tools (Google Developer tools is preferred choice), I can see that the outgoing http request for my layer of interest is exactly the same between the refresh call – and the pan/zoom call. I have also verified the sql contained in the layer definitions, and am positive the layers/features returned in the refresh call are definitely wrong.

Anyone have any ideas as what may be causing this? Better yet, does anyone know an alternate way to refresh a layer without panning/zooming the map?

A couple of other notes:

I have disabled cacheing at the client via setDisableClientCaching
My sql where clauses make use of IN statement. Is this a bad idea with file geodatabases?

Best Answer

I believe that analysisResultLyr.setLayerDefinitions(layerDefinitions); will trigger a refresh automatically after updating the layer definitions see https://developers.arcgis.com/javascript/3/jsapi/arcgisdynamicmapservicelayer-amd.html#setlayerdefinitions. I think your call to refresh may be interfering with some async behaviour with the layer definition updates. Try removing it.

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I'm sure there is a better way of doing this but here is how I did it:

I stored the layers to be added in a module level variable (layersToAdd) and in each layer onLoad event I pushed the layer in to this array. I then called a function addLayers which checked if the length of addLayers was equal to the total layers to be added. The function sorts the array based on index and then adds them.

For the missing layer in the onError event I removed the item from the array and called addLayer.

There will be a performance hit but I couldn't think of another way. I guess another option would be to add the layers as soon as they are available and then re-order the layers once the total count is reached.

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Replace getImageUrl and modify the url before passing it to the callback:

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